JSFiddle - React, Tailwind, and code Playground

HTML

<fieldset class="parent fieldset-width">
    <div class="child">
        <div class="grandchild">
            asdf
        </div>
    </div>
</fieldset>

<div class="parent">
    <div class="child">
        <div class="grandchild">
            asdf
        </div>
    </div>
</div>

CSS

.parent {
    border: 1px solid green;
    padding: 20px;
    margin: 20px;
}

.child {
    border: 1px solid red;
    padding: 20px;
    overflow: auto;
}

.grandchild {
    border: 1px solid #ccc;
    width: 2000px;
    padding: 10px;
}

JavaScript

$(document).ready(function() {
   $(".fieldset-width").css("width", $(window).width() - 82);
 });

$(window).resize(function() {
    $(".fieldset-width").css("width", $(window).width() - 82);
});